Ask the Expert Question-and-Answer Archive

by Ron Joseph

November, 2002

Painting Concrete Floor

Q.I am in the process of having asbestos vinyl tiles (AVT) removed from my basement floor. This will be done a licensed abatement contractor. When the process is done there will residue from the mastic used to lay the tiles. What steps can be used to paint over this?

A. You should remove as much as the mastic as possible. If you can't scrape it off, then use a solvent, such as mineral spirits. If that doesn't work, then try lacquer thinners. In any event, use as little thinners as you can and don't pour large quantities on the floor. When you have removed as much of the mastic as possible, you should thoroughly wash the floor with a detergent cleaner and then rinse off with clean fresh water. Allow the floor to thoroughly dry and then you can apply the floor coating of your choice.

If you use the thinners to remove the mastic make absolutely sure that you have adequate ventilation in the basement to remove the solvent vapors quickly. Remember, the solvents are flammable and if you have a furnace or other ignition source in the vicinity of the solvent vapors, you could start a fire or explosion. Therefore, be VERY, VERY cautious.

Also, if you use the thinners (solvents) wear proper protective clothing, including a suitable respirator that you can purchase from an industrial paint supply store. Always play it safe and I suggest that you read the safety instructions that come with the paints and solvents.